Such a mobile radio device, such a mobile radio network control unit and such a method are known within the context of the mobile radio system UMTS (Universal Mobile Telecommunications System).
A UMTS mobile radio system normally has a core network (CN), a mobile radio access network (UMTS Terrestrial Radio Access Network, UTRAN) and also a large number of mobile radio terminals (User Equipment, UE). In UMTS, a transmission mode is provided, called FDD (Frequency Division Duplex) mode, which involves separate signal transmission taking place in the uplink direction (uplink direction denotes a signal transmission direction from a mobile radio terminal to a respective base station in the mobile radio access network) and in the downlink direction (downlink direction denotes a signal transmission direction from a respective base station associated with the mobile radio terminal in the mobile radio access network to the mobile radio terminal) through separate allocation of frequencies or frequency ranges.
For the purpose of transmitting data between a mobile radio terminal and a respective base station in a mobile radio cell, UMTS defines an air interface which is divided into three protocol layers. An overview and a detailed description of the air interface protocol layers based on UMTS can be found in 3GPP TS 25.301, Technical Specification, Third Generation Partnership Project; Technical Specification Group Radio Access Network; Radio Interface Protocol Architecture (Release 1999).
One of the three protocol layers of the UMTS air interface is known as the Radio Resource Control (RRC) protocol layer. The RRC protocol or the RRC protocol layer is responsible for setting up and clearing down and also for (re)configuring physical channels, transport channels, logical channels, signalling radio bearers and radio bearers, and also for negotiating all parameters of the protocol layers of layer 1 and layer 2 on the basis of UMTS. To this end, the units of the RRC layer in the mobile radio terminal and in the mobile radio network control unit use the signalling radio bearers to interchange appropriate RRC messages, as described in 3GPP TS 25.331, Technical Specification, Third Generation Partnership Project; Technical Specification Group Radio Access Network; RRC Protocol Specification (Release 1999).
For the purpose of management, generally the management of mobile radio transmission resources in the mobile radio terminal within the context of the uplink packet data transmission, it is known that the mobile radio terminal communicates information about the volume of data traffic in a transport channel to a mobile radio network control unit (Radio Network Controller, RNC) at the level of the RRC protocol layer. This is done using “measurement report messages”. In this connection, as table 1 below shows, data buffer storage filling levels, i.e. the filling level of the data buffer storages in the RLC units, for the transport channel in question are indicated to the currently competent mobile radio network control unit. In other words, this means that in line with 3GPP TS 25.331, Technical Specification, Third Generation Partnership Project; Technical Specification Group Radio Access Network; RRC Protocol Specification (Release 1999) the mobile radio network control unit is sent notification at the RRC layer level regarding how many data items to be transmitted there are at present in the buffer storages in the RLC units of the respective mobile radio terminal.
In this connection, mobile radio transmission resources are to be understood, in particular, to mean the transmission power of the mobile radio terminal, the number and also the spreading factor of the allocated CDMA codes.
Table 1 shows an example of such a measurement report list, as described in 3GPP TS 25.331, Technical Specification, Third Generation Partnership Project; Technical Specification Group Radio Access Network; RRC Protocol Specification (Release 1999):
TABLE 1InformationElement/GroupType andSemanticsnameNeedMultireferencedescriptionTrafficOP1 tovolume<maxRB>measurementresults>RB IdentityMPRB Identity10.3.4.1 6>RLC BufferOPEnumeratedIn bytesPayload(0, 4,And N8, 16,Kbytes = N*102432, 64,bytes. Twelve128, 256,spare values512, 1024,are needed.2K, 4K,8K, 16K,32K, 64K,128K, 256K,512K, 1024K)>Average ofOPEnumeratedIn bytes AndRLC Buffer(0, 4,NPayload8, 16,Kbytes = N*102432, 64,bytes. Twelve128, 256,spare values512, 1024,are needed.2K, 4K,8K, 16K,32K, 64K,128K, 256K,512K, 1024K)>Variance ofOPEnumeratedIn bytes AndRLC Buffer(0, 4,NPayload8, 16, 32,Kbytes = N*102464, 128, 256,bytes. Two512, 1024, 2K,spare values4K, 8K, 16K)are needed.
Using this information, the mobile radio network control unit can configure the mobile radio terminal as appropriate, for example in order to restrict or expand the usable transport formats of a mobile radio terminal or to perform handover to another mobile radio cell, reconfiguration of the dedicated physical channels or an RRC state change, particularly from a first RRC state CELL_DCH to a second RRC state CELL_FACH.
The measurement result list shown in Table 1 is thus transmitted from an RRC unit in the mobile radio terminal to the RRC unit in the corresponding mobile radio network control unit, and the respective RRC data buffer storage filling level is indicated for each radio bearer (RB).
The standardization committee 3GPP (3rd Generation Partnership Project) is currently, as described in RP 040081, Proposed Work Item on FDD Enhanced Uplink, TSG RAN Meeting #23, Phoenix, USA, Mar. 10 12 2004, working on improving the packet data transmission via dedicated transport channels in the uplink, i.e. for the uplink direction at the UMTS air interface for the FDD mode, with a view to increasing the data throughput and the transmission speed. To achieve better differentiation from the already existing dedicated transport channel DCH, a new dedicated transport channel called Enhanced Dedicated Channel (E-DCH) has been introduced for this purpose. The fundamental characteristics of this new transport channel include the application of a Hybrid Automatic Repeat Request method (HARQ method) based on the N-channel stop&wait method, scheduling controlled by the base station, also called NodeB in UMTS, and also frame lengths of less than or equal to 10 ms.
The N-channel stop&wait HARQ method is a transmission protection method in which a mobile radio terminal has a number of N “HARQ processes” configured for it, with an HARQ process representing a respective instance of the stop&wait method. For each HARQ process, the data are transmitted to the network and are buffer-stored until the network receives acknowledgement of correctly received data (Acknowledgement, ACK). Otherwise, i.e. if the data have not been received correctly (Negative Acknowledgement, NACK), the data are transmitted to the network again.
The NodeB controlled scheduling is a method in which the scheduling in the mobile radio terminal, i.e. the selection of an appropriate transport format from a set of defined transport formats for the E-DCH transport channel, is controlled such that the nodeB can temporarily restrict or expand a mobile radio terminal's use of transport formats from the set of defined transport formats for the E-DCH transport channel on the basis of the traffic situation in the respective radio cell.
To date, however, a decision has not yet been made regarding the details of how the data about the new transport channel E-DCH are to be transmitted via the UMTS air interface. One possible solution is to split the data according to their priorities over various data buffer storages, known as Priority Queues (PQ), which are then processed and hence transmitted with preference or with less preference according to their importance, i.e. their priority.
As set out above, a transmission protection method (HARQ method) is applied in which the network sends the mobile radio terminal an acknowledgement about correctly or incorrectly received data. The mobile radio terminal contains various data buffer storages for this function too, in order to buffer-store the data prior to acknowledgement of correct receipt.
Both functions are performed within the MAC protocol layer in the newly provided subprotocol layer, i.e. what is known as a Medium Access Control Enhanced Uplink (MAC-e) entity, which is present, i.e. implemented, both on the terminal and on the network. On the network, the entity executing the communication protocol based on MAC-e can be found in the NodeB, i.e. in the UMTS base station.
In addition, UMTS communication standard release 5 for the downlink (downlink transmission direction) contains a method, called High Speed Downlink Packet Access (HSDPA), for improving the air interface for the packet data transmission via the shared transport channel High Speed Downlink Shared CHannel (HS-DSCH). In comparable fashion to the enhanced uplink medium access control protocol, the fundamental characteristics of the HSDPA method are based on the application of an N-channel stop&wait HARQ method, NodeB controlled scheduling and frame lengths of less than 2 ms. These functions are performed in the medium access control subprotocol layer MAC-hs (Medium Access Control High Speed), with the units which implement the MAC-hs protocol being provided both on the terminal and on the network, in this case usually in a mobile radio base station.
The MAC-hs subprotocol layer receives the data which are to be processed in the downlink transmission direction, i.e. the protocol data units which are processed in the MAC-hs subprotocol layer, from the MAC-d subprotocol layer using “MAC-d flows” in the form of MAC-d protocol data units, which correspond to the MAC-hs service data units (SDU). The protocol data units formed by the MAC-hs subprotocol layer, i.e. the “MAC-hs PDUs”, are transmitted via the transport channel called HS-DSCH to the physical transmission layer, which then uses the air interface to transmit them via the physical channel HS-PDSCH (High Speed Physical Downlink Shared Channel) to a subscriber terminal.
An MAC-hs protocol data unit comprises an MAC-hs header field (header) and one or more MAC-hs SDUs. In each transmission time interval (TTI) of 2 ms, it is possible to transmit a maximum of one MAC-hs PDU. The MAC-hs control data header, i.e. the header field of the MAC-hs PDU, has a variable length. In the MAC-hs subprotocol layer, the data to be transmitted are buffer-stored in data buffer storages, known as Priority Queues (PQ), according to their priority. In line with the MAC-hs subprotocol, as described in 3GPP TS 25.321, Technical Specification, Third Generation Partnership Project; Technical Specification Group Radio Access Network; Medium Access Control (MAC) Protocol Specification, all the MAC-hs SDUs in a transmission time interval belong to the same priority queue, i.e. in each transmission time interval only MAC-hs SDUs having the same priority are transmitted on an HS-DSCH transport channel.
In line with the HSDPA method, a “Transport Format Resource Indicator” (TFRI) is provided which is transmitted to the individual subscriber terminals in a respective mobile radio cell via the physical channel called High Speed Shared Control CHannel (HS-SCCH). Using the Transport Format Resource Indicator, the respective subscriber terminal can derive the respective sizes of the transport blocks of an MAC-hs PDU in line with 3GPP TS 25.321, Technical Specification, Third Generation Partnership Project; Technical Specification Group Radio Access Network; Medium Access Control (MAC) Protocol Specification. Signals are thus sent to indicate the size of the respective MAC-hs PDU which is being transmitted on the associated HS-PDSCH.
In line with the HSDPA method, in each data transmission time interval the data from just one priority queue are transmitted via the HS-DSCH, which is why the control data header of an MAC-hs protocol data unit has a very simple structure and it is necessary to transmit only the information regarding the priority queue from which the data to be transmitted originate.
In line with the UMTS Enhanced Uplink method, on the other hand, the data having various priorities, i.e. the data from various priority queues, are transmitted in an MAC-e protocol data unit within a data transmission time interval.
One possible solution to signalling the association of an MAC-e SDU, i.e. an MAC-d PDU, for example, with a respective priority queue and with a respective MAC-d data stream would be to add to each MAC-e SDU a control data header with an identification of the respective MAC-d flow (flow-ID, FID) and then to add a control data header with an identification of the respective priority queue (queue ID, QID) to every single data packet from a priority queue before transmission, so as then to be able to split the data at the receiver again as appropriate in the data link layer.
However, this would be disadvantageous on account of the enormous volume of additional signalling data in the control data header (large overhead) which is required.
In line with the HSDPA method, the TFRI is used to signal the size of an MAC-hs protocol data unit. This is disadvantageous in the case of E-DCH particularly because data from various priority queues need to be transmitted in each data transmission time interval.
On the basis of the prior art, it is thus merely possible to signal the total size of an MAC-e protocol data unit but not how the data of an MAC-e protocol data unit need to be made up, i.e. from which priority queues how many and using what packet size it is necessary to transmit data in an MAC-e protocol data unit.